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Special Article
Practice parameter: Steroids,
acyclovir, and surgery for Bell’s
palsy (an evidence-based review)
Report of the Quality Standards Subcommittee of the
American Academy of Neurology
Patrick M. Grogan, MD; and Gary S. Gronseth, MD Article abstract—Objective: To determine the effectiveness of steroids, acyclovir, and surgical facial nerve decompression
in Bell’s palsy. Methods: The authors identified articles by searching MEDLINE and selected those that prospectively
compared outcomes in patients treated with steroids, acyclovir, or surgery with patients not receiving these modalities.
The authors graded the quality of each study (class I to IV) using a standard classification-of-evidence scheme. They
compared the proportion of patients recovering facial function in the treated group to the proportion of patients recovering
facial function in the control group. Results: The authors identified no adequately powered class I studies for any
treatment modality. The pooled results of two class I and two class II studies showed significantly better facial outcomes
in steroid-treated patients compared with non–steroid-treated patients (relative rate good outcome 1.16, 95% CI 1.05 to
1.29). One class II study demonstrated a significant benefit from acyclovir in combination with prednisone compared with
prednisone alone (relative rate good outcome 1.22, 95% CI 1.02 to 1.45). All studies describing outcomes in patients
treated with facial nerve decompression were graded as class IV. Conclusion: For patients with Bell’s palsy, a benefit from
steroids, acyclovir, or facial nerve decompression has not been definitively established. However, available evidence
suggests that steroids are probably effective and acyclovir (combined with prednisone) is possibly effective in improving
facial functional outcomes. There is insufficient evidence to make recommendations regarding surgical facial nerve
decompression for Bell’s palsy. Well-designed studies of the effectiveness of treatments for Bell’s palsy are still needed.
The Quality Standards Subcommittee of the Ameri- achieve near normal function.3 The disease is com- can Academy of Neurology is charged with develop- mon, with an annual incidence of 20 per 100,000.
Thus, despite its good prognosis, Bell’s palsy leaves diagnostic procedures, treatment modalities, and more than 8,000 people in the United States each clinical disorders. The selection of topics for which year with permanent, potentially disfiguring facial practice parameters are developed is based on preva- lence, frequency of use, economic impact, member- Commonly employed, noncontroversial treatment ship involvement, controversy, urgency, external modalities for Bell’s palsy include eye patching and constraints, and resources required. This report ad- lubrication to protect the cornea.4 Controversy re- dresses the effectiveness of controversial therapies mains regarding the effectiveness of commonly used pharmacologic therapies—steroids and acyclovir—as Bell’s palsy is an acute, peripheral facial paresis of well as surgical facial nerve decompression.
unknown cause.1 Usually, the diagnosis is estab- Although the etiology of Bell’s palsy remains un- lished without difficulty in patients presenting with clear, there are reasons to believe steroids, acyclovir, unexplained unilateral isolated facial weakness.2 or facial nerve decompression might improve out- Most patients with Bell’s palsy recover without comes in patients with this disorder. Bell’s palsy treatment—71% achieve complete recovery, 84% may result from inflammation and subsequent me- Approved by the Quality Standards Subcommittee on July 29, 2000. Approved by the Practice Committee on August 5, 2000. Approved by the AAN Board ofDirectors on October 7, 2000.
Received July 21, 2000. Accepted in final form February 3, 2001.
Address correspondence and reprint requests to the American Academy of Neurology, 1080 Montreal Avenue, St. Paul, MN 55116.
Copyright 2001 by AAN Enterprises, Inc.
chanical compression5 of the facial nerve in the tem- plete facial function. We also calculated the 95% CI poral bone, possibly initiated by the herpes simplex virus.6 Steroids might reduce facial nerve inflamma- In studies using the House and Brackmann facial tion, and surgery might relieve facial nerve compres- function scoring system,7 we considered an outcome sion, whereas acyclovir might treat the putative of grade I or II a good recovery. When comparing the proportion of patients recovering complete facial To determine if steroids, acyclovir, and surgical function, we considered an outcome of grade I a com- facial nerve decompression are effective in improving plete recovery. In studies using the Adour/Swanson facial functional outcomes in Bell’s palsy, we performed grading scale,8 we considered a facial paralysis re- a systematic review and analysis of the literature.
covery profile (FPRP) of greater than seven and a Based on this review, we propose recommendations recovery index (FPRI) of greater than five a good recovery. We considered an FPRP of 10 and an FPRIof 10 a complete recovery.
Process.
Identification and selection of studies.
When necessary to improve the precision of the We searched the National Library of Medicine’s measured RR, we pooled the results from different MEDLINE database from 1966 to June 2000. Three studies using general variance-based meta-analytic searches were performed in which we combined the techniques.9 To minimize the risk of bias in the re- term “facial paralysis or Bell’s palsy” with “pred- sulting summary estimate of effect, we pooled stud- nisone or prednisolone or hydrocortisone,” “acyclo- ies with the lowest risk of bias first, adding studies vir,” and “surgery.” We subsequently screened the with a higher risk of bias only when necessary to resultant articles and their references for those stud- ies that compared outcomes in prospectively assem- bled Bell’s palsy patients treated with steroids, grade of class III or better were considered in the acyclovir, or surgery to concurrent patients not formulation of the recommendations. We formulated practice recommendations after considering the esti- mated effect sizes, the significance of the effect, and sign characteristics were extracted from the identi- the consistency of the effect between studies.
To account for the quality of evidence, we deter- mined a strength-of-recommendation level for each recommendation using the scheme in Appendix 2.
Age, sex, severity of palsy, and duration of palsy We determined the strength of recommendation based on the number and quality of studies available Medication regimen used or decompression proce- to derive the estimate of effect. Thus, for example, an intervention demonstrating a consistent and signifi- cant benefit in two class I studies would earn a level Percentage of patients completing the study.
“A” recommendation. We planned to recommend Method of facial function outcome assessment, in- such an intervention as established as effective. An intervention demonstrating a consistent and signifi- We graded the quality of the evidence provided by cant effect in two class II studies would earn a level each study (class I, II, III, IV) using the classification- “B” recommendation and would be recommended as of-evidence scheme in Appendix 1. In this scheme, class probably effective. Similarly, an intervention demon- I studies are judged to have a low risk of bias and class strating a consistent and significant benefit in two IV studies are judged to have a high risk of bias. Stud- class III studies would earn a level “C” recommenda- ies were graded independently by each author. Differ- tion. We planned to recommend such an intervention ences were resolved after discussion.
using two-by-two tables, we compared the proportion Analysis.
In patients with Bell’s palsy, do steroids of patients recovering good facial function in the improve facial functional outcomes? treated group to the proportion of patients recover- identified 230 articles that described steroid use for ing good facial function in the control group by calcu- the treatment of Bell’s palsy. Nine8,10-17 of these stud- lating the relative rate (RR) by means of the ies prospectively compared outcomes in patients treated with oral steroids to concurrent patients whowere not treated with steroids. The characteristics of RR ϭ ͓A/͑A ϩ C͔͒/͓B/͑B ϩ D͔͒.
these studies are listed in table 1.
Recovery
Good Poor
tients meeting standard diagnostic criteria for Bell’s Treated A
palsy were allocated to treatment with steroids or placebo. Most studies limited enrollment to adults.
One study17 enrolled children only. The proportion of In separate analyses, we calculated the RR at patients with severe facial weakness in each study which patients in the treated group recovered com- varied considerably (0 to 91%). The time allowed April (1 of 2) 2001
Table 1 Design characteristics and outcomes in controlled studies of patients with Bell’s palsy treated with steroids
Severity, Duration, Follow-up, Completion Completion rate: percentage of subjects followed to study completion; severity: percentage of patients with complete palsy; duration: maximum duration of palsy before starting ste- Rx ϭ medication; CI ϭ 95% confidence interval; NH ϭ natural history, percentage of non–steroid-treated patients attaining a good outcome; RR ϭ relative rate of steroid-treated patients attaining outcome compared to non–steroid-treated patients; NS ϭ not stated.
from symptom onset to treatment allocation also var- less likely to have hypertension. Because hyperten- ied widely between studies (2 to 14 days).
sion is an independent risk factor for poor facial out- With the exception of one study11 that used hydro- comes,1 a spurious association between steroids and cortisone, authors used oral prednisone or pred- improved facial outcomes may have resulted.
nisolone. Authors from another study12 did not Because of unmasked, nonindependent outcome specify the corticosteroid used, but we assumed it assessments, as well as other methodologic flaws, was prednisone because the dosage was similar to we graded the evidence from four studies8,15-17 as other studies using this medication. Multiple dosage regimens of oral steroids were used. The most com- monly reported regimen was 1 mg/kg of oral pred- or complete recovery in steroid-treated patients rela- nisone, up to 70 mg per day, split into twice-daily tive to untreated patients. Although included in the dosing. The starting dose was continued for 6 days, table for completeness, because of a high risk of bias, then tapered off over a subsequent 4 days. Outcomes the results of class IV studies will not be discussed in most studies were determined after 6 or more The results of the five class I, II, and III studies We graded the evidence from two studies10,11 as were mixed. The two class I studies10,11 and one class class I. In both, patients were randomly allocated to II study12 did not show significantly better outcomes steroids or placebo, no patients were lost to follow- in steroid-treated patients. However, these studies up, and outcomes were assessed in a masked were insufficiently powered to exclude a clinically important effect from steroids. One class II13 and one We graded the evidence from two studies as class class III14 study demonstrated significantly better II.12,13 One class II study12 employed a quasi- outcomes in the steroid-treated patients. In these randomization technique (every other patient). This studies, patients with Bell’s palsy were 1.2 times as may have unmasked treatment allocation. We likely to attain good facial functional recovery as un- graded a second study13 as class II because 29% of treated patients. No study showed significantly worse facial functional outcomes in patients treated We graded one14 nonrandomized, unmatched, con- with steroids. Four of five of the studies demon- trolled study with masked outcome assessments as strated a trend for better outcomes in the steroid- class III. In this study, there were important con- founding baseline differences between steroid- No study showed a significant difference in the time to recovery between steroid-treated patients example, steroid-treated patients in this study were and controls. One class I study10 reported a median April (1 of 2) 2001
time to recovery of 45 days in both steroid-treatedand untreated patients. One class II13 and one class Istudy11 reported a trend for steroid-treated patientsto recover faster than did control patients, but thedifferences were not significant. The average numberof days to recovery were 51 vs 69 and 63 vs 69,respectively.
None of the class I, II, or III studies described a significant decrease in the frequency of autonomicsynkinesis (e.g., “crocodile tears”) in patients treatedwith steroids.
Some authors have suggested that steroids work best in patients with Bell’s palsy if started early.18The articles reviewed provided little evidence to sup- Figure. Relative rates of good outcomes (rectangles) with port or refute this assertion. Most of the patients 95% CI (vertical lines) in steroid-treated patients com- enrolled in these studies were treated within 1 week pared with non–steroid-treated patients. Pooled relativerate of class I and II studies is indicated by vertical of onset of facial paralysis. The class III study14 showed a nonsignificant trend of more benefit in pa-tients who received steroids early (by day 1: RR 1.25;by day 2: RR 1.19; by day 3: RR 1.12).
However, the RR derived from this class III study mation regarding the response of Bell’s palsy patient was also the most prone to bias. The nonrandom subgroups, such as patients with diabetes mellitus, treatment allocation employed in this study resulted hypertension, or recurrent facial palsy. Thus, we in prognostically important differences between were unable to determine if the association between steroid-treated and non–steroid-treated patients.
steroid treatment and facial outcomes was different These confounding differences may have resulted in a spurious association between steroids and im- Bell’s palsy patients with incomplete facial paral- ysis have excellent outcomes regardless of therapy.3 To increase the precision of the measured RR Thus, some have suggested that patients with com- while minimizing the risk of bias, we statistically plete facial palsy benefit most from steroids.15 The pooled the rates from the two class I studies. The studies reviewed here provided little evidence rela- pooled result from these studies10,11 did not demon- tive to this issue. In a two-way analysis of variance strate a significant benefit from steroids (RR 1.01).
of time to recovery, one class II study13 found no However, the 95% CI of the combined RR was still interaction between treatment and the severity of too wide (0.80 to 1.27). The pooled result was insuffi- facial weakness at the onset of treatment.
To further increase precision, we combined the RR roid side effects. Side effects occurred in 1 to 4% of of good facial recovery from the class I and class II treated patients. These side effects, in descending studies. While increasing the precision of the derived order of frequency, were dyspepsia, loss of blood RR of recovery, including the class II studies in- sugar control, recurrent duodenal ulcers, mood creased the risk of bias in the summary estimate of swings, and acute psychosis. All effects resolved effect. The pooled RR from the two class I and two class II studies demonstrated a significant associa- tion between steroids and good outcomes (RR 1.16, in steroid-treated patients relative to non–steroid- 95% CI 1.05 to 1.29, vertical diamond in the figure).
treated patients extracted from each study are plot- Thus, assuming 80% of patients with Bell’s palsy ted in the figure. The measured RR are ordered, left attain good facial outcomes without steroid treat- to right, by class of evidence. The 95% CI are repre- ment, an additional 14% might attain good outcomes if treated with steroids. The pooled effect from the None of the studies reviewed were conclusive. The class I and II studies was homogenous (p ϭ 0.59) RR with the lowest risk of bias came from the class I with overlapping CI. This suggests that the differ- studies.10,11 Both employed random, masked method- ences in the study results were potentially related to ologies. Although at low risk for bias, the measured RR from these class I studies were the least precise.
This is indicated in the figure by the tall CI. These ciently powered class I studies, we conclude that a class I studies enrolled too few patients to defini- benefit of steroids in Bell’s palsy has not been defin- tively exclude an important effect (either benefit or itively established. However, the available evidence supports a level “B” recommendation using the A more precise measure of the effect of steroids scheme in Appendix 2. Thus, based on the pooled came from the single class III study.14 In this study, result of class I and class II studies and a relatively authors enrolled the largest number of patients.
benign side effect profile, we conclude that steroids April (1 of 2) 2001
Table 2 Design characteristics and outcomes in controlled studies of patients with Bell’s palsy treated with acyclovir
Completion rate: percentage of subjects followed to study completion; severity: percentage of patients with complete palsy; duration: maximum duration of palsy before starting ste- Rx ϭ medication; CI ϭ 95% confidence; NH ϭ natural history, percentage of non–acyclovir-treated patients attaining a good outcome; RR ϭ relative rate of acyclovir-treated pa- tients attaining outcome compared to non–acyclovir-treated patients; NS ϭ not stated.
are safe and probably effective in improving facial mine if the side effects reported were secondary to functional outcomes in patients with Bell’s palsy.
In patients with Bell’s palsy, does acyclovir im- studies, we conclude that a benefit of acyclovir in egy identified 92 articles that described acyclovir use Bell’s palsy has not been definitively established.
for the treatment of Bell’s palsy. Three19-21 of these However, the available evidence supports a level “C” studies prospectively compared outcomes in treated recommendation using the scheme in Appendix 2.
patients with those not treated with acyclovir. Study Thus, based on the result of a single class II study characteristics and outcomes of these studies are and a relatively benign side effect profile, we con- clude that acyclovir (combined with prednisone) is safe and possibly effective in improving facial func- tients meeting standard diagnostic criteria for Bell’s tional outcomes in patients with Bell’s palsy.
palsy were allocated to treatment with acyclovir or In patients with Bell’s palsy, does facial nerve de- prednisone. Two studies19,21 compared the effect of a compression improve facial functional outcomes? combination of acyclovir and prednisone vs pred- We found 104 articles describing surgical facial nisone alone. One study20 compared acyclovir alone nerve decompression in patients with Bell’s palsy.
to prednisone alone. The dose of acyclovir varied be- Four12,22-25 of these studies prospectively compared tween studies from 1,000 mg a day for 5 days to outcomes in patients treated with surgery to those 2,400 mg a day for 10 days. Outcomes were mea- not treated. The characteristics and outcomes of sured after 3 to 12 months of follow-up.
these studies are listed in table 3.
One study19 employed randomized treatment allo- cation and masked outcome assessments. However, meeting standard diagnostic criteria for Bell’s palsy 17% of enrolled patients were lost to follow-up. For were allocated to treatment with facial nerve decom- this reason, we graded evidence from this study as pression or medical therapy. The majority of patients class II. Because of unmasked, nonindependent out- in each study had complete facial paralysis and for come assessments, as well as other methodologic this reason had poorer prognoses.1 Most had been flaws, the evidence from the two remaining stud- treated with steroids. Authors reported varied surgi- cal approaches. Outcomes were measured after 6 to or complete recovery in acyclovir-treated patients Patients were not randomly allocated to surgical relative to patients treated with prednisone alone.
and nonsurgical groups in any study. Additionally, The single class II study19 demonstrated a signifi- no study described masked or independent assess- cant benefit of acyclovir. In this study, patients ment of facial functional outcomes. For these rea- treated with acyclovir and prednisone were 1.22 sons, the evidence from all of these studies was times more likely to attain good outcomes than pa- tients treated with prednisone alone (95% CI 1.02 to 1.45). Thus, assuming 80% of patients with Bell’s or complete recovery in patients undergoing facial palsy attain good outcomes on steroids alone, an ad- nerve decompression relative to nonsurgical patients ditional 18% might attain good outcomes if treated from each of the class IV studies. Only one study22 demonstrated a significant association between sur- ture of side effects in the acyclovir trials were similar to those with steroids.19-21 It was impossible to deter- was the most common serious side effect from facial April (1 of 2) 2001
Table 3 Design characteristics and outcomes in controlled studies of patients with Bell’s palsy treated with facial nerve decompression
Severity, Duration, Follow-up, Completion Completion rate: percentage of subjects followed to study completion; severity: percentage of patients with complete palsy; duration: maximum duration of palsy before starting ste- CI ϭ 95% confidence interval; NH ϭ natural history, percentage of nonsurgical patients attaining a good outcome; RR ϭ relative rate of surgically treated patients attaining out- come compared to non–surgically treated patients; NS ϭ not stated.
nerve decompression reported in these articles. The Masked, standardized outcome assessments, in- study published in 198212 reported deafness in 15% of patients undergoing facial nerve decompression.
Sufficient power to detect important differences More recent trials report much lower complication Subgroup analyses to detect interactions between treatment, severity of paralysis, duration of palsy scribing facial outcomes in surgically treated Bell’s before initiation of therapy, and patient characteris- palsy patients was too high to support evidence- tics such as the diabetes mellitus, hypertension, and based conclusions. Additionally, serious complica- tions, including permanent hearing loss, werereported from surgical facial nerve decompression.
Disclaimer.
For these reasons, we were unable to develop educational service of the American Academy of evidence-based recommendations for the use of facial Neurology. It is based on an assessment of current nerve decompression in patients with Bell’s palsy.
scientific and clinical information. It is not intendedto include all possible proper methods of care for a Practice recommendations.
particular neurologic problem or all legitimate crite- ria for choosing to use a specific procedure. Neither Early treatment with oral steroids is recom- is it intended to exclude any reasonable alternative mended as probably effective to improve facial func- methodologies. The AAN recognizes that specific care decisions are the prerogative of the patient and Early treatment with acyclovir in combination the physician caring for the patient, based on all of with prednisone is recommended as possibly effective to improve facial functional outcomes (Level C).
There is insufficient evidence to make recommen- Acknowledgment
dations regarding the use of facial nerve decompres-sion to improve facial functional outcomes (Level U).
The authors thank the members of the Quality Standards Sub-committee of the American Academy of Neurology, Wendy Ed-lund, the AAN Manager, Clinical Practice Guidelines, and Alison Recommendations for future research.
Nakashima, AAN Administrator, Clinical Practice Guidelines, for preceding recommendations are based on the best their time, expertise, and efforts in developing this document. Theauthors also thank Rollin J. Hawley, MD, FACP, Viliam J. Fur- available evidence regarding the effectiveness of ste- dik, MD, and William Bishop, MD, for their role in initiating this roids, acyclovir, and facial nerve decompression for Bell’s palsy. All of the studies reviewed had flaws,including insufficient statistical power and bias- Appendix 1
prone methodologies that preclude definitive conclu- Definitions for classification of evidence
sions. Definitive studies of the effectiveness of these Class I. Evidence provided by a randomized, controlled clinical modalities are still needed. Investigators contem- trial (RCT) with masked outcome assessment in a representative plating such studies should carefully weigh the risk population. The following are required: a) primary outcomes are of the intervention relative to its potential benefit.
clearly defined; b) exclusion and inclusion criteria are clearly stat- The design of such studies should include the following: ed; c) adequate accounting of dropouts and crossovers with num-bers sufficiently low to have minimal potential for bias; and d) Random allocation to treatment groups.
relevant baseline characteristics are substantially equivalent Complete follow-up of enrolled patients.
April (1 of 2) 2001
Class II. Evidence provided by a prospective matched group geniculate ganglion of a patient with Bell’s palsy. Ann Otol cohort study in a representative population with masked outcome assessment that meets a through d above or an RCT that lacks 7. House JW, Brackmann DE. Facial nerve grading system. Oto- laryngol Head Neck Surg 1985;93:146 –147.
Class III. All other controlled trials (including well-defined 8. Adour KK, Wingerd J, Bell DN, Manning JJ, Hurley JP. Pred- natural history controls or patients serving as their own controls) nisone treatment for idiopathic facial paralysis (Bell’s palsy).
in a representative population where outcome assessment is inde- 9. Petitti DB. Statistical methods in meta-analysis. In: Petitti Class IV. Evidence from studies not assessing outcomes inde- DB. Meta-analysis, decision analysis and cost-effectiveness pendent of treatment, uncontrolled studies, case series, case re- analysis. New York, NY: Oxford University Press, 1994;90 – 10. May M, Wette R, Hardin WB, Sullivan J. The use of steroids Appendix 2
in Bell’s palsy: a prospective controlled study. Laryngoscope Definitions for strength of recommendations
11. Taverner D. Cortisone treatment of Bell’s palsy. Lancet 1954; Level A. Established as effective, ineffective, or harmful for the given condition in the specified population. Usually, an “A” recom- 12. Brown JS. Bell’s palsy: a 5-year review of 174 consecutive mendation requires that the pooled result from two or more dis- cases: an attempted double blind study. Laryngoscope 1982; tinct class I studies demonstrates a consistent, significant, and 13. Austin JR, Peskind SP, Austin SG, Rice DH. Idiopathic facial Level B. Probably effective, ineffective, or harmful for the given nerve paralysis: a randomized double blind controlled study of condition in the specified population. Usually, a “B” recommenda- placebo versus prednisone. Laryngoscope 1993;103:1326 –1333.
tion requires that a single class I study demonstrates a significant 14. Shafshak TS, Essa AY, Bakey FA. The possible contributing and important effect or the pooled result from two or more distinct factors for the success of steroid therapy in Bell’s palsy: a class II studies demonstrates a consistent, significant, and impor-tant effect.
clinical and electrophysiological study. J Laryngol Otol 1994; Level C. Possibly effective, ineffective, or harmful for the given condition in the specified population. Usually, a “C” recommenda- 15. Wolf SM, Wagner JH, Davidson S, Forsythe A. Treatment of tion requires that a single class II study demonstrates a signifi- Bell palsy with prednisone: a prospective randomized study.
cant and important effect or the pooled result of two or more distinct class III studies demonstrates a consistent, significant, 16. Abraham–Inpijn L, Oosting J, Hart AA. Bell’s palsy: factors affecting the prognosis in 200 patients with reference to hy- Level U. Data are inadequate or conflicting. Given current pertension and diabetes mellitus. Clin Otolaryngol 1987;12: knowledge, treatment is unproven and an evidence-based recom- 17. Unuvar E, Oguz F, Sidal M, Kilic A. Corticosteroid treatment of childhood Bell’s palsy. Pediatr Neurol 1999;21:814 – 816.
Appendix 3
18. May MM, Schlaepfer WM. Bell’s palsy and the chorda tym- pani nerve: a clinical and electron microscopic study. Laryngo- Quality Standards Subcommittee Members: Gary Franklin, MD, MPH (Co-Chair); Catherine Zahn, MD (Co-Chair); Milton 19. Adour KK, Ruboyianes JM, Von Doersten PG, et al. Bell’s Alter, MD, PhD; Stephen Ashwal, MD; John Calverley, MD; Rich- palsy treatment with acyclovir and prednisone compared with ard M. Dubinsky, MD; Jacqueline French, MD; Michael Glantz, prednisone alone: a double blind, randomized, controlled trial.
MD; Gary Gronseth, MD; Deborah Hirtz, MD; Robert G. Miller, Ann Otol Rhinol Laryngol 1996;105:371–378.
MD; James Stevens, MD; and William Weiner, MD.
20. De Diego JI, Prim MP, De Sarria MJ, Madero R, Gavilan J.
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